Beavers have amazing construction and engineering skills; they are among few animals that make dramatic changes to their environment to provide shelter for themselves and their young. Beavers are semiaquatic, which means they spend much of their time in water, usually streams, rivers, and lakes. These hardworking creatures build dams using sticks, branches, mud, and anything else they can find to change the course of a stream, sending some of the stream’s water to flood another area in order to create a small pond. In that pond they can then build a lodge, a large, domed structure where the beaver family can spend the winter. The lodge is built of the same materials used for the dam.
Beavers use their long, powerful teeth to cut down branches and even whole trees. They then drag or float the wood over to the site of the lodge, sometimes using canals, or narrow passages filled with water, that they built themselves. They pack the sticks together using mud, which freezes in the winter, turning the beaver lodge into a strong fort that predators can’t get into. While the lodge itself sticks out above the surface of the water (sometimes nearly six feet, or almost two meters), the entrance to the lodge is underwater, giving the beavers further protection. In the months before winter approaches, beavers begin stockpiling food, including water plants, branches, and leaves. They anchor their food stash in the water just outside the lodge’s entrance, so throughout the winter their food supply is nearby.
Beavers have thick, shiny coats that have long been attractive to people in the fur trade. The North American beaver nearly became extinct in the 1930s due to extensive trapping for its fur. Another notable feature of these animals is their broad, flat tails that can be up to a foot long in some larger beavers. Beavers use their tails to steer when they are swimming and to help prop them up when they are standing. They also use them to communicate with other beavers, slapping their tails on the water to produce a loud warning sound when a predator approaches.